The cartoon appeared in the San
Francisco Chronicle and elsewhere, including the
Bizarro web site. The image was of a petri dish in a lab with
tiny maternal speck giving parental advice to an even tinier speck:
"You can be anything you want to be when you grow up."
Artist Dan Piraro said the cartoon was his favorite of the
week because of its “strangeness.”

Piraro wrote on his blog,

The cartoon did not differentiate
between embryonic and adult cells, much less reprogrammed adult
cells. Using reprogrammed cells in the cartoon would have been even
creepier and cooler, giving new meaning to the 1947 song, “I Am My
Own Grandpa.”(See here and here.)

(A nod to "Bob" for calling our attention to the cartoon.)